Wisconsin birders are looking forward to an excellent finch winter! 

Birds that usually winter in Canada are moving south. These atypical “irruptive migrations” are usually caused by changes in winter food availability and can occur in several northern species especially finches, owls and evening grosbeaks. This year finch species that normally winter in Canada and the northern United States are ranging farther south due to a massive crop failure of fruit and cone bearing trees in Canada.  Birding expert and Ontario resident Ron Pittaway compiles local seed crop and late summer bird observations to create a detailed “Winter Finch Forecast”  available through Ebird every autumn. The Wisconsin Ebird group uses the Pittaway data to create detailed forecasts for our area. Based on the two forecasts we should expect to see Red and White-winged Crossbills, Redpolls, Pine Grosbeaks, Pine Siskins, and Evening Grosbeaks joining resident Goldfinches, House and Purple Finches this winter in northeastern Wisconsin.

Pine Grosbeaks are large finches with heavy black bills and gray sides and red washed black back and reddish pink rump.

Pine Grosbeaks have been steadily moving into the state in small flocks. Look for them on the UW—Green Bay campus feeding on crab apples, especially near the Kress Center. This is a taiga species which is considered an irruptive winter visitor across the Midwest and east.  The last really large widespread movement into Wisconsin was in 1977 and again in 1985. They love to dine on crabapples, high bush cranberries, left over apples in orchards, sumac, mountain ash, and when food supplies are exhausted, the seeds of the box elder ash. Pine Grosbeaks will also switch to backyard feeders when black sunflower seeds are offered, but for now, it is find the fruit trees first!!

Evening Grosbeaks are striking birds, identifiable by their large pale bills and black, white, and bright yellow coloration.

Evening Grosbeaks have been on the decline in Wisconsin in recent years and are usually only seen reliably in the far north of the state. Evening Grosbeaks nest as close as Lakewood, Oconto County, annually. However, based on arrival data, the birds being seen now are coming from the northwest. Observations were reported from Duluth as birds rounded Lake Superior. So far this year there are a few reports in Oconto, southern Brown, and Manitowoc counties.  Their preferred seeds are box elder and other maple species. They will also visit platform feeders supplied with black oil sunflower seeds.

Red and White-winged Crossbill species have staged a massive irruption into Wisconsin. Although these birds are unlikely to come to backyard feeders, look for them in conifer swamps and bogs in the far North, the Green Bay area, and in conifer groves along the Lake Michigan Lake shore from Manitowoc down to Chicago. Interestingly, according to Ebird, the Red crossbills arriving in Wisconsin are from western Canada escaping a hemlock seed crop failure in the Pacific Northwest.

Common Redpolls, Pine Siskins, and Goldfinches are common winter residents throughout northeastern Wisconsin and while abundant are not occurring in higher than expected numbers. Purple Finches have apparently moved on and are now below expected numbers. House Finch populations are way up after declining for a number of years. These birds prefer small seeds including birch, alder, willow, tamarack, and weedy field forbs. They will visit backyard nyjer (thistle) and black oil sunflower seed offered in feeders.

Two non-finch species are also irrupting south in response to the seed failures in Canada.

Bohemian Waxwings, while not finches, are another fruit loving bird that is irrupting southward because of the Canadian fruit crop failure and are expected to appear in large numbers in our area this year. In fact a flock of over 250 Bohemian Waxwings seen in Door County was recently reported to Ebird. These birds are voracious fruit feeders so look for them in urban or natural areas with fruit bearing trees like mountain ash, Juniper, and crabapples. These assertive birds will compete with Pine Grosbeaks for access to fruit trees. Bohemian waxwings form pure flocks of their own species or in mixed flocks with Cedar Waxwings.

Bohemian Waxwings are very similar to Cedar Waxwings. Bohemians are larger and have black, yellow, and white wing bars.

Rose-breasted Nuthatches feed on conifer seeds and so are also arriving in high numbers from the same northern regions because of the cone failure. They are often seen at platform feeders eating sunflower seeds and also will feed at suet feeders.

Feeding Finches:

Ebird recommends that people hoping to attract winter finches to their yards put out platform or other large flat surface feeders with black oil sunflower seeds. All finches like small seeded sunflower seeds and some finches like Goldfinches, Redpolls and Siskins also will feed on nyjer in tube or bag feeders. Most finches are attracted to water, so maintaining a heated bird bath or water feature will bring birds to your yard.

It is going to be a very delightful finch winter. 

More Information:

•  Tom Erdman contributed to the text and Tom Prestby provided photos

• Wisconsin Ebird’s detailed “Winter Finch Update” provides an update on the status of Wisconsin’s winter finch flight so far, maps of sightings, and tips on finding these species in your neck of the woods: http://ebird.org/content/wi/news/wisconsin2019s-winter-finch-update-1-1
• Birding expert Ron Pittaway has been publishing a Winter Finch Forecast for several years. Access  his yearly forecast on ebird: http://ebird.org/content/ebird/news/ff2012
• Read  more about the irruption of red breasted nuthatches in“The Pathless Wood”, a blog by Ottowa naturalist Gillian Mastromatteo: http://meadowhawk.wordpress.com/tag/ron-pittaway/
• Ebird is a real-time, online checklist program run by the Cornell Lab of Ornithology and the National Audubon Society. The website provides access to basic information on bird abundance and distributions. http://ebird.org/content/ebird/
• UW—Green Bay graduate student and Biodiversity Center technician Tom Prestby took the photos for this blog entry. See his other fabulous bird photos at http://www.pbase.com/tprestby

Purple and yellow Coneflower (upper left), Prairie Dock (upper right), Culver’s root (lower left), and Compass Plant (lower right).

The colorful jewels of the prairie are the forbs or showy flowering plants.  These plants produce flowers that attract insect or hummingbird pollinators and are often showy and colorful. Flowers in the prairie are primarily yellows and purples, which attract insects like bees and butterflies.  The most common tall plants you will see in flower in mid-July through August include  Compass Plant (Silphium laciniatum), Prairie Dock (Silphium terebinthinaceum), Rosinweed (Silphium integrifolium), many species of Goldenrods (Solidago Spp.), Black-eyed Susan (Rudbeckia hirta), Purple Coneflower (Echinacea purpurea), Rattlesnake Master (Eryngium yuccifolium), Culver’s Root (Veronicastrum virginicum), Yellow Coneflower (Ratibida pinnata), and Wild Bergamot (Monarda fistulosa).  

Nodding Pink Onion (upper left), Purple Prairie Clover (upper right), White Prairie Clover (lower left), and Spotted Bee Balm (lower right).

When the prairie was planted, careful consideration was made to match different plants to their preferred soil conditions (e.g. water moisture, productivity).  As a result, the numbers and types of flowers vary in different parts of the prairie, even from year to year, in response to weather conditions.  A careful observer will be rewarded with a display of flowers that bloom below the grasses and tall  forbs.  Some of the species to look for are Purple Prairie Clover (Dalea purpurea) and White Prairie Clover (Dalea candida), which are adapted to dry soils; and Bush Clover (Lespedeza capitata), Spotted Bee Balm (Monarda punctata), and Nodding Pink Onion (Allium cernuum), which are adapted to mesic (moderately damp) soils.

The Keith White Prairie is alive with color in the summer and fall and is always a great place to walk. You never know what plants or animals you might see.

Are you trying to decide between working out at the gym and taking a walk in the woods? If you are interested in improving your mental, as well as your physical health, new research recommends heading for the woods.

A quiet path through Mahon Woods in the Cofrin Arboretum on the UW--Green Bay campus.

Most people would probably agree that a walk in the woods (barring mosquitoes) has a reviving effect on our mental well-being. Writers, from Pliny to Thoreau, have touted the recuperative benefits of nature. Frederick Law Olmsted, the Landscape Architect who founded The Clearing, located in Door County, WI, wrote in 1865 “the enjoyment of scenery employs the mind without fatigue and yet exercises it; tranquilizes it and yet enlivens it; and thus, through the influence of the mind over the body, gives the effect of refreshing rest and reinvigoration to the whole system.” In 1985 E. O. Wilson explored this love of nature in his book “Biophilia”. In it he championed the idea that our attraction to nature goes beyond the aesthetic to the genetic, that our love of nature is actually genetically programmed.

A new study led by Richard Mitchell of the Centre for Research on Environment, Society and Health, at Glasgow University agrees with Wilson’s assertion. They looked at the locations that 1800 physically active people chose for exercise and then compared that data to measures of their mental health. Interestingly, only activity in the natural environment was associated with a lower risk of poor mental health. Those that chose to exercise in woodlands or parks had a 50% greater effect on positive mental health compared to those who chose the gym. The study also indicates that the positive effects of activity in a natural area cause a physiological change that goes beyond the effect of positive thought. Our biology actually changes when we experience nature.

There have been a number of theories that have been proposed to try to explain the physiological beneficial influence of nature, but probably the two best-known theories are the Attention Restoration Theory of Kaplan and Kaplan (1989) and the psycho-evolutionary theory developed by Ulrich and his colleagues in the 1990s. These theories explain the influence of nature, especially plants, on the reduction of stress and mental fatigue. Both theories consider the recovery effects of viewing nature to have a biological cause.

Attention restoration theory suggests that fatigue caused by trying to concentrate on a project in the face of continued distractions can be restored by quiet exercise and reflection in a natural environment. It is based on the assumption that natural settings are “quietly fascinating” and draw our attention without our even realizing it. We observe nature in a way that requires no effort, and is pleasing because it creates a sense of order and meaning. However, watching nature is not so attention grabbing that it prevents the reflective thought that allows us to recover from mental fatigue. Natural settings, they argue, also reduce stress because they create a feeling of “getting away” or escaping from the work environment.

Another theory, developed by Ulrich and Parson in the 1990s, argues that our modern world is over-stimulating because it is too visually complex and loud. They argue that natural settings reduce stress because they mimic the natural habitats that we evolved in. We are drawn to and have a positive psychological response to natural settings like woodland edges, grassy meadows and ponds and stream edges. Visiting natural spaces like the Cofrin Arboretum or other natural areas speeds recovery from stress.

Other studies agree with the results reached by Mitchell and his colleagues. Studies by several Japanese researchers have shown that forest walks result in lower blood pressure, pulse rates and cortisol levels, as well as increased heart healthy hormones. A study by Jo Barton and Jules Pretty in 2010 determined that spending just five minutes walking in an outdoor natural setting caused improved mental and emotional health. A study by Roe and Aspinall (2010) found that rural walks had a more restorative effect on mental health than urban walks did. They also found that those with poorer mental health saw even greater restorative effect from walking in a rural landscape. In a different study they found that when children with extreme behavior problems spent time in forest settings, they developed positive emotional responses, like improved trust, over time (Roe and Aspinall 2011).

What is the take home message? Go take a walk in the woods. Nature can help those of us that live and work in complex stressful environments to be physiologically healthier if we take the time to visit natural areas to de-compress. There is a positive biological effect on your body when you experience trees, vegetation, streams and ponds.

Four of UW—Green Bay’s natural areas, The Cofrin Arboretum, Point au Sable, Kingfisher Farm, and Toft Point, provide walking trails. Plan your next walk outside and enjoy the benefits of greater health!

Links:

• Regular exercise in natural environments halves risk of poor mental health: http://www.gla.ac.uk/news/headline_236113_en.html
• Barton, J.  and Pretty, J. (2010) What is the Best Dose of Nature and Green Exercise for Improving Mental Health? A Multi-Study Analysis. Environ. Sci. Technol., 2010, 44 (10), pp 3947–3955
• R. Kaplan and S. Kaplan. (1989) The experience of nature: A psychological perspective. New York: Cambridge University Press.
• Roe, J. and Aspinall, P. (2011): The restorative benefits of walking in urban and rural settings in adults with good and poor mental health, Health & Place 17, 103-113
• Roe, J. and Aspinall, P. (2011): The emotional affordances of forest settings: an investigation in boys with extreme behavioural problems. Landscape Research.
• Ulrich, Roger S., Robert F. Simons, Barbara D. Losito, Evelyn Fiorito, Mark A. Miles, and Michael Zelson. 1991. Stress recovery during exposure to natural and urban environments. Journal of Environmental Psychology 11: 201-230.
• Wilson, Edward O. (1984). Biophilia. Cambridge: Harvard University Press.

Everyone has noticed how strange our spring weather has been this year. One thing you might be wondering is why this occurred, or how this weather affects the natural world. The study of the timing of natural events is called phenology. There are three main factors that affect phenology 1) sunlight 2) temperature and 3) precipitation. Some examples of phenology include when migrating birds return, when plants first flower, and when lakes freeze and reopen. It is important to keep phenological records. By keeping records it allows us to look at the changes over the years at different geographic regions. This also helps us understand interactions between organisms and their environment and the effects of climate change. The Cofrin Arboretum Center for Biodiversity keeps records of important natural events in the western Great Lakes region during all months of the year. These records can be accessed at http://www.uwgb.edu/biodiversity/phenology/. The Wisconsin State Climatology Office also holds an impressive database which you can access at http://www.aos.wisc.edu/~sco/. 

Why is phenology so important? Over the years we observe that phenological events vary. Ecosystems are able to recover from variation between years but when these changes happen consistently over a long period, the timing of events (flowering, leafing, migration, and insect emergence) can impact how plants and animals thrive in their environments.  The success and survival of an ecosystem depend on the timing of phenological events. For example, if the timing of emergence of leaves changes it can result in fewer seeds/insects which would impact animals that depend on those seeds/insects for food. Consider the difference in spring vegetation in the Cofrin Arboretum between May 4th of  2010 and 2011. Early leaf-out can result in a longer growing season and better habitat as long as a late freeze does not kill tender vegetation or developing flowers or fruits.

Prairie Pond in the Cofrin Arboretum shown on May 4th in 2010 (left) and 2011 (right).

 On the Wiscoonsin Statewide Monthly Temperature for the last 12 months graph it is shown that the monthly average temperature for this year is obviously higher when compared to the normal monthly temperature.

Figure courtesy of the Wisconsin State Climatology Office website.

 This temperature increase leads to sooner blooming of flowers and plants as well as earlier date arrivals for some migratory birds. This year the early migratory birds have to fight a little harder to survive. On the cold days when there aren’t any insects small birds have a more difficult time staying warm and full because they have nothing to eat. If they would have waited to return at their normal migration date they may not have this type of problem. Everything is inter-linked in nature and the weather plays a key role in determining what survives and what doesn’t. It will be exciting to watch this interesting weather continue throughout the year.

Spring brings many new things with it as it approaches (rather early this year I might add). One of the most interesting and entertaining things I have experienced is Prairie Chicken Booming. I had no idea what to expect on this trip, but I was in for a real treat.

On the trip, the group hid from the birds in plywood blinds like the one shown above.

 Prairie Chickens are one of four native grouse (Ruffed Grouse, Sharp-Tailed Grouse, and Spruce Grouse). Prairie Chickens prefer grasslands for nesting, brood-rearing, roosting, feeding, and loafing. They also prefer wide horizons which allow them to see and be seen for great distances.

A male Prairie Chicken inflates the orange air sacs located on the side of their neck as he displays to a female.

What is Prairie Chicken Booming? It is the courting of a female Prairie Chicken by multiple anxious male suitors. In the spring, males (cocks) gather on booming grounds or leks. Males battle each other for the small territories (50 feet in diameter) with displays, postures, and physical combat. Cocks occupy the same territories every morning during the mating season. At the end of these battles some of the males end up pretty battered and bloodied. Besides fighting for the ladies’ attention, cocks advertise with foot stomp dances, displaying feathers, orange eyebrows and air sacs, snapping tail feathers, and “booming” which can be heard greater than one mile away on still mornings. Booming is a three note call that is enhanced by their inflated air sacs. When females (hens) are present, cocks intensity their displays by adding a “whoop” to their three note boom. As I sat out in the brisk morning air I compared the Prairie Chickens to cartoon characters with their eccentric jumping and curious sounds.

Prairie Chickens have a pretty interesting back-story as well. In the early 1900’s Prairie Chickens flourished and were hunted until 1955. Grassland habitat began to disappear due to farming, tree planting, and natural succession and in turn the Prairie Chicken numbers plunged. The best remaining populations were in central Wisconsin and initial land was acquired on the Buena Vista Marsh in 1954.  Drs. Frederick and Frances Hamerstrom were instrumental when it came to the preservation of this species. They both studied under Aldo Leopold who was an avid environmentalist and brilliant professor from the University of Wisconsin. The Hamerstroms revolutionized wildlife study with their work on Prairie Chickens. Through their research and commitment they preserved the existence of Prairie Chickens in Wisconsin. It is because of them that we still have this unique bird in our state.

You know those scenes in movies where the main character is standing on the edge of a cliff and all of the sudden the ground falls out beneath him and he drops into the water? In Great Lakes communities, that is an actual concern for some people.

There has been an increasing demand for a new standard of care to be upheld in the Great Lakes. People demanded that we not just minimize harm but also rehabilitate the Great Lakes. In February 2009 President Obama proposed a $475 million Great Lakes Restoration Initiative Action Plan. The Great Lakes Restoration is now a National Priority.

There are five significant ecosystem problems in the Great Lakes.

• Toxic Substances and Areas of Concern (e.g. pollution prevention and clean up)
• Invasive Species
• Nearshore Health and Nonpoint Source Pollution (e.g. reduce polluted runoff from urban, suburban, and agricultural sources)
• Habitat and Wildlife Protection and Restoration
• Accountability, Education, Monitoring, Evaluation, Communication, and Partnerships

The green color of the bay comes from chlorophyll present in algae.

Where does the Biodiversity Center fit into all of this? The Center is hosting a workshop that will be held at UWGB on June 19, 2012. This workshop focuses on developing online tools to help local decision-makers address hazard related threats and effects of climate change on Great Lakes communities. For example, if a company wanted to build on a bluff near Lake Michigan they would have to talk to a zoning director about how close to the edge of the bluff they can build. The zoning director could use these online tools to figure out how far away from the edge the building has to be so it won’t be at risk of falling into the water someday due to bluff erosion. The goal of this project is for coastal communities to have a better understanding of how they may be impacted by the hazards of a changing climate, and to provide new tools and information for developing adaptive plans.

At this workshop, decision makers will have the opportunity to interact with the online tools. The tools incorporate geospatial data, science-based information, and visualizations. The goal is for decisions-makers to understand and document the effects of “proposed projects” and what liabilities those projects may create for the community. At the workshop, the instructor will propose a project and the users can use the tools to consider if the project will:

• Accelerate/amplify existing hazards (e.g. erosion and flooding)
• Increase infrastructure costs and liabilities related to flooding and shoreline protection
• Worsen resource management challenges associated with water quality, habitat conservation, and the public trust doctrine
• Decrease the economic, cultural, physical, and ecological resilience of natural and built coastal environments

After the workshop, the users will give their feedback based on their experience with the online program. This feedback is vital in determining how beneficial these online tools will be for local officials in their decision making tasks.

There are four main categories for the online tools.

• Hazards Management and Planning: this section of the online tools is based on demographic data, land use and parcel data, hazard and flood maps, and climatology data (e.g. extreme temperatures, precipitation change, and flood events).
• Coastal Erosion and Bluff Recession Prediction: the section demonstrates the connections between weather and climate conditions, coastal recession, bluff retreat hazards, and shoreline management strategies.
• Coastal Infrastructure Planning: the section focuses on coastal structures including their maintenance costs, effectiveness and regional impacts (e.g. hardened shorelines, recreational and commercial use).
• Habitat Conservation and Restoration Planning: this section focuses on protecting the region’s key ecosystem resources, especially maintaining the protective and beneficial functions of natural floodplains.

The National Oceanic and Atmospheric Administration (NOAA) Coastal Services Center and Association of State Floodplain Managers are key partners for this project.

1. American Crow
2. Killdeer
3. Herring Gull
4. Ring-billed Gull
5. Double-crested Cormorant
6. Lesser Scaup
7. American White Pelican
8. Mallard
9. Mourning Dove
10. Common Goldeneye
11. Red-breasted Merganser
12. Northern Cardinal
13. Redhead
14. Greater Scaup
15. American Black Duck
16. American Wigeon
17. Gadwall
18. Purple Martin
19. Tree Swallow
20. Song Sparrow
21. Canada Goose
22. American Robin
23. Blue Jay
24. White-throated Sparrow
25. Wild Turkey
26. Brown-headed Cowbird
27. Red-winged Blackbird
28. Black-capped Chickadee
29. European Starling
30. Common Grackle
31. Bald Eagle
32. Ruddy Duck
33. Great Egret
34. House Wren
35. American Goldfinch
36. Chipping Sparrow
37. Eastern Bluebird
38. Barn Swallow
39. Lesser Yellowlegs
40. Northern Rough-winged Swallow
41. Cooper’s Hawk
42. House Sparrow
43. Cliff Swallow
44. Yellow-bellied Sapsucker
45. White-breasted Nuthatch
46. Downy Woodpecker
47. Red-bellied Woodpecker
48. Northern Flicker
49. Yellow-rumped Warbler
50. Blue-gray Gnatcatcher
51. Red-tailed Hawk
52. House Finch
53. Rock Pigeon
54. Sandhill Crane
55. Great Horned Owl
56. Turkey Vulture

Patrick Robinson

By Chelsea Gunther

Patrick Robinson, an adjunct faculty member and Cofrin Center for Biodiversity affiliate, is working on a project examining the effects of climate change, both socially and ecologically. He is working on this project along with other researchers from the University of Wisconsin-Madison, University of Wisconsin-Extension, and National Oceanic and Atmospheric Administration (NOAA) Cooperative Oxford Laboratory in Maryland.

So what is NERRS? It is the National Estuarine Research Reserve System. This system contains 28 diversely located reserves. These reserves are being exposed to several human-related (anthropogenic) and climate-related stressors. The goal of this project is to understand how climate change impacts coastal areas and categorize each reserve based on the results of the anthropogenic and climate impacts. The team plans to present the project results in the fall of 2012.

Whose idea was it? NOAA’s Climate Program Office is developing a partnership with the Office of Ocean and Coastal Resource Management. It is their goal to understand how climate change impacts coastal areas.

How do they plan on doing this? The team is taking a three step approach. First they analyze and synthesize key data describing physical, ecological, and socio-demographic characteristics in these areas. Second, they isolate the main anthropogenic and climate stressors impacting the reserves. Examples of anthropogenic stressors are nutrient enrichment, sedimentation, hypoxia, and physical disturbance including water diversions. Examples of climatic stressors are sea level rise, precipitation frequency and intensity, and drought. Third, from the data they have gathered they will categorize each reserve based on their results to those stressors. Assigning each reserve to different categories allows the research team to better assess the impacts from humans as well as climate on these coastal ecosystems.

Why are they doing this? NOAA hopes to continue further investment in this program and share the information learned with similar projects.  The research will help prioritize future environment vulnerability assessments and planning efforts.

The Red River Breaks are a part of the St. Louis River Freshwater Estuary and Lake Superior National Estuarine Research Reserve.

A new reserve, the Lake Superior NERR, was designated in Wisconsin in 2010 (see lsnerr.uwex.edu/). Patrick, along with many others, worked for over four years on the designation process for the reserve. The Lake Superior NERR represents only the second reserve on the Great Lakes, with the other being in Ohio on Lake Erie. 

Last week I was at a concert where two large fresh-cut trees had just been brought in. I noticed several insects lazily flying about the auditorium and when one landed nearby we recognized it as a cluster fly.  I knew that cluster flies overwinter in attics and walls like Asian Ladybugs, but I wondered if they could also overwintering in Christmas trees. Last year I had seen these same insects shortly after we brought in a fresh-cut Christmas tree as well. Did they come in on the trees?

Cluster fly larvae are non-native imports from Europe.  They are not considered invasive in northeastern Wisconsin because they are parasites on earthworms, which are also not native to our area.  In the autumn adult flies search out protected over-wintering sites. In the wild these would be under bark or in dense vegetation or other crevices in rocky piles or cliff faces. Of course buildings mimic cliff faces to these insects, and the flies will cluster under siding and in walls or attics. Christmas tree farms are likely to provide good overwintering sites if there are brush piles or dead trees or sheds nearby. But it isn’t too likely they could use living Christmas trees successfully because there are few good places for them to hide.

I spoke with UW Madison entomologist Phil Pellitteri who agreed the flies are unlikely to find good winter protection in Christmas trees and suggested that the flies were probably in the building and were roused by warm outside temperatures. Wherever they came from they are slow and easy enough to catch. Unlike other “house” flies, cluster flies do not feed in our houses and are unlikely to spread disease.

Cluster Fly (Phormia rudis). Photo by Gary Fewless.

Are cluster flies a pest? That probably depends on how many there are in one place. They can sometimes accumulate inside walls and attics in large numbers. When temperatures rise on warm days some flies become active and make their way into living spaces. Once inside, they are not easily controlled by pesticides. Experts at the Entomology department at Penn State  and UW Extension suggest killing flies trapped in walls or attics might makes matters worse because the dead flies will attract other more onerous pests like carpet beetles that would  invade closets and rugs looking for wool and furs after they devour the flies.

Real Christmas trees are clearly the better choice for the environment when compared with artificial trees. They sequester carbon, produce less pollution and waste when recycled, and tree farms provide habitat that helps to preserve local biodiversity. Sometimes people are worried about that biodiversity, especially insects or spiders, coming inside with their trees. The best way to remove any stowaways is to give the tree a good shake before bringing it in the house. Fresh Christmas trees should never be sprayed with chemical pesticides, which are flammable and environmentally unfriendly. And of course sprays would ruin that wonderful fresh conifer scent.

References:

Phillip Pellitteri, University of Wisconsin Diagnostic Laboratory: http://www.entomology.wisc.edu/diaglab/

Insect Advice from Pennsylvania State Extension: http://ento.psu.edu/extension/factsheets/cluster-flies

University of Wisconsin Extension News: “Homeowners find fall insects unwelcome guests.” http://www.uwex.edu/news/read.cfm?id=153

The Nature Conservancy “Real versus fake Christmas trees” http://www.nature.org/photosmultimedia/real-vs-fake-christmas-trees.xml

The borders of the Lenfestey Family Courtyard are heavily planted with elderberries and each August and September as they ripen I have great views out my window of the birds that come to feast. There are always the usual bunch, the robins and their young that nested all summer in the Serviceberry, Cardinals of course, and the flocks of Cedar Waxwings that easily navigate the tangle of branches like bands of pirates finding the richest caches of fruit.

Eastern Kingbirds foraging on elderberries. Shot through my office window. Note the textbook reflected by the flash.

But there are Eastern Kingbirds joining the party too. Kingbirds rarely visit the courtyard, preferring the open edges of the trail near the ponds where they gracefully dive and roll, capturing flying insects in their pincer-like beaks. It is strange to see them flapping through the dense foliage of the elderberries, where they tip themselves forward off the branches as they clumsily pluck berries one by one. And while they seem a bit unfamiliar with the technique they do manage to gorge themselves with fruit.  Fruit-eating also coincides with a remarkable tolerance in this notoriously aggressive species. Kingbirds will flock together during migration and in their South American wintering grounds.

Scientists have long recognized this feeding switch from insects to fruit in several species of primarily insectivorous birds shortly before and during migration.  It was originally thought that the birds switched to fruit as insect populations declined, but this does not seem to be the case. It was also hypothesized that fruit might provide more calories, but nutrition studies showed that while some species did gain weight on fruit others lost weight (Smith et al. 2007).  Other research has focused on the advantages of feeding on fruit.  Insects require a lot more energy to find and capture and are usually caught on the wing, exposing birds to migrating hawks. Berries offer an easily collected high density food source and the foliage offers cover from hawks and other predators.  Studies have also shown that birds do seek out berries that are highest in proteins and lipids (Parrish, 1996).

Just this year scientists have started to look at micronutrients including antioxidants in fruit. Migration is extremely stressful and scientists speculate that ingesting more antioxidants might improve these birds ability to survive during migration and in tropical wintering grounds where birds are packed closer together (McCue et al. 2010).

It has even been suggested by ornithologist Gene Morton (1971)  that the white tip on the Eastern Kingbird’s tail might analogous to the bright tail feathers of the waxwings. As they forage tail flicks signal food locations to others in the flock .

Regardless of the physiological reasons migratory birds are switching to fruit, the take-home message is strong.  Make sure that migrating birds have access to reliable sources of fruit in the fall. Both Parrish’s and McWilliams’ research suggests that native berries, are superior in nutrition to non-native species. We need to make sure that we preserve native habitats along migratory routes so that birds have reliable high quality food during stop-overs.

Parrish (1996) also argues for us to become better land stewards of our own yards. “Conserving native habitat in a backyard is simple and inexpensive,” he said.  “Many songbirds will even use small, yard-sized patches of these natural landscapes during migration, providing people with exciting opportunities for bird observation–and providing the birds with the critical fuel for a long journey south.”

References

McCue, M. D., O. Sivan, S.R. McWilliams, and B. Pinshow (2010) Tracking the oxidative kinetics of carbohydrates, amino acids, and fatty acids in the house sparrow using exhaled 13CO2. Journal of Experimental Biology, in press.

Parrish, Jeffrey D. (1997) Patterns of Frugivory and Energetic Condition in Nearctic Landbirds during Autumn Migration. The Condor Vol. 99, No. 3 (Aug., 1997), pp. 681-697

Morton, Eugene S. (1971) Food in migration habits of the Eastern Kingbird in Panama. The Auk: 88: 925-926.

Smith, Susan B., Kathleen H. Mcpherson, Jeffrey M. Backer, Barbara J. Pierce, David W. Podlesak, and Scott R. Mcwilliams (2007) Fruit Quality and Consumption by Songbirds During Autumn Migration . The Wilson Journal of Ornithology 119(3):419–428

Turner, Scott (1996) Study shows songbirds switch from bugs to berries to fuel fall migration. Brown University news Bureau. http://www.brown.edu/Administration/News_Bureau/1996-97/96-019.html